Choroidal Thickness Changes in Patients with Neovascular Age-Related Macular Degeneration Treated with Anti-Vascular Endothelial Growth Factor Therapy

Abstract

Purpose: : To evaluate the change in choroidal thickness as measured by spectral domain optical coherence tomography (SD-OCT) in patients with neovascular age-related macular degeneration (NVAMD) undergoing anti-VEGF therapy.

Methods: : Patients with a diagnosis of NVAMD in at least one eye were retrospectively reviewed to identify those who had at least 12 months of follow-up SD-OCT data. All patients underwent OCT imaging using either the 3D-OCT-1000 (Topcon Medical Systems) or the Cirrus HD-OCT (Carl Zeiss Meditec). For each case, subfoveal choroidal thickness (SCT) was measured from Bruch’s membrane to the choroid-sclera junction using digital calipers in validated OCT review software. SCT measurements were performed at baseline (just before the start of anti-VEGF therapy in the case of treated eyes) and at the last follow-up date after start of therapy. SCT measurements were performed independently by two masked graders using a standardized reading center protocol, and all discrepancies were adjudicated. Only cases in which the full extent of the choroid was visible were included in subsequent quantitative analyses. SCT measurements were correlated with other patient and treatment characteristics including number and duration of treatments.

Results: : 89 eyes of 52 patients with a mean follow-up of 22 months (SD 7.0) for non-treated eyes (n=37) and 23 months (SD 6.7) for treated eyes (n=52) met our inclusion criteria. Mean age was 85 years (range 69 to 97), and 57 % were female. Eyes in the treatment group received a mean of 8.8 (SD 8.1) intravitreal anti-VEGF injections of Ranibizumab (5.7), or Bevacizumab (3.1) each. SCT at baseline was 157.7 µm (SD 87.9) for untreated eyes and 142.5 µm (SD 77.4) in the treated group (p=0.416). The average reduction in SCT over time was observed to be 11.6 µm (p=0.007) and 14.5 µm (p=0.0001) for the respective groups. However, change in SCT did not differ significantly between the two groups (p=0.562), and did not correlate with the number of re-treatments (p=0.552). Neither visual acuity at baseline (p=0.618), last follow-up (p=0.174), or the change in visual acuity over time (p=0.429) correlated significantly with SCT.

Conclusions: : Although choroidal thickness decreased over time in eyes with neovascular AMD, intravitreal anti-VEGF therapy did not appear to accelerate or otherwise alter this decline.

Keywords: age-related macular degeneration • choroid: neovascularization • injection